The Yamaha NS-555 is a 3-way, bass reflex, and STANDALONE tower speaker not tied to any specific Yamaha series. Its bass-reflex design can be used for main channels and features dual 6-1/2” Polymer-Injected Mica Diaphragm (PMD) cone woofers, a 5” midrange cone driver, and a 1” aluminum dome tweeter. Both the midrange and tweeter utilize Yamaha’s exclusive waveguide horns, which ensure that sound waves reaching one’s ears are coming directly from the unit, rather than being reflected off the walls. Additional features of the Yamaha NS-555 include an internally-wired ‘Monster Cable’ that ensures a clear signal, magnetic shielding for protection from TV/Video-monitor signals, and a Bi-Wiring Capability—separate +/- terminals for the woofer(s) and other driver(s) reduces modulation in distortion.